In Project 6 we will assess exposures to atmospheric PCBs among an urban cohort of children and their[unreadable] mothers in a heavily contaminated area where dredging and filling of PCB-laden sediments will occur during[unreadable] the study period. Exposures will be assessed through repeated air sampling over four years inside and[unreadable] outside of homes of subjects and at local schools and also through annual blood collection and assay for[unreadable] PCB congener profiles. These exposures will be compared to a rural site with the goal of characterizing[unreadable] atmospheric PCB exposures in high and low exposure residential cohorts. The urban site (East Chicago, IN)[unreadable] has a legacy of PCB contamination from intense past industrial activity whereas the rural site (Columbus[unreadable] Junction, IA) is without local sources of PCBs. The overall goal of the study is to establish airborne[unreadable] exposures of ethnically mixed populations, most and least at risk for adverse health outcomes from[unreadable] the more volatile PCBs. The following Specific Aims are proposed: Aim 1) Establish a residential cohort[unreadable] (n=108) in East Chicago. Aim 2) Establish a residential cohort (n=108) in Columbus Jet. Aim 3) Measure[unreadable] emissions and exposures of atmospheric PCBs at homes and schools over 4 years in the urban and rural[unreadable] cohorts. Aim 4) Gather demographic, residential, occupational, activity and dietary information from subjects[unreadable] by questionnaire. Aim 5) Analyze data from these cohorts and develop an exposure model for the atmospheric[unreadable] PCB congeners. The Indiana Harbor and Canal Dredging Project will place 4.5 million cubic yards of[unreadable] PCB-contaminated sediment into a confined disposal facility (CDF) located within 1/2 km of the middle and[unreadable] high school in East Chicago. Thus, we will perform air and blood monitoring of nearby residents before and[unreadable] during dredging and CDF filling and characterize determinants of exposure. Four primary hypotheses will be[unreadable] tested: H,: Residents of East Chicago have significantly higher exposures to atmospheric PCBs and (H2:)[unreadable] significantly higher blood levels of atmospheric PCB congeners than people living in rural Iowa. H3: In the[unreadable] urban cohort and the rural cohort, the body burden of the atmospheric PCB congeners of adolescent subjects[unreadable] are significantly correlated with those of their mothers. H4: Residents of East Chicago will experience[unreadable] significantly increased exposures to atmospheric PCBs and increased blood PCB concentrations associated[unreadable] temporally with the dredging of Indiana Harbor and placement of sediments in the confined disposal facility.